1. Field of the Invention
The present invention relates to a display device, and, in particular, to a display device having a structure for electrically connecting electrode films which are formed in different layers of a substrate.
2. Description of the Related Art
In a display device such as a liquid crystal display device, a plurality of conductive layers are formed, with a layer of insulating material therebetween, over an array substrate forming a part of the display device. In order to electrically connect the lines existing in such a plurality of conductive layers, an interlayer switching section as shown in FIGS. 25 and 26 may be used in some cases. FIG. 25 is a plan view showing an interlayer switching section of related art and FIG. 26 is a cross sectional diagram along an A-A cutting line of FIG. 25.
The array substrate has a multilayer structure comprising a gate electrode film GM, a gate insulating film GI provided over the layer of the gate electrode film GM, a drain electrode film SDM provided over the gate insulating film GI, a passivation film provided over the layer of the drain electrode film SDM, and a conductive film SC provided over the passivation film. In the example configuration of FIGS. 25 and 26, the passivation film comprises a layer of an inorganic insulating film PAS and a layer of an organic insulating film FPS provided over the layer of the inorganic insulating film PAS.
In the interlayer switching section, on the array substrate, a first contact hole CH1 which reaches the gate electrode film GM and a second contact hole CH2 which reaches the drain electrode film SDM are formed, and the interlayer switching section comprises the conductive film SC. The conductive film SC is formed to include the inside of the two contact holes including regions where the electrode films are exposed, and a region of a surface of the passivation film between the contact holes. With the interlayer switching section, a line formed in the layer of the gate electrode film GM and a line formed in the layer of the drain electrode film SDM can be electrically connected to each other.
JP 2004-46223 A discloses an interlayer switching section which electrically connects the lines existing in a plurality of conductive layers.
In the interlayer switching section of the array substrate in the above-described display de vice, of the region of the conductive film SC, the region connecting between the two contact holes CH1 and CH2 is exposed over the passivation film. Because of this, when a physical contact occurs in this region, there is a possibility of disconnection.